It has been conventionally known that a liquid composition for oral cavity is filled in a container which enables discharging the content in the form of foam, thereby directly applying a foam composition to the oral cavity through a discharge port upon use to provide feeling of use and the like characteristic of such foam. Various surfactants are used in such a composition in order to achieve desired performances.
For example, in Patent Literature 1, a liquid agent for oral cavity containing dextranase and a nonionic surfactant such as polyoxyethylene hardened castor oil is directly injected into the mouth at a specified foam density to result in an increase in retaining property of the dextranase in the plaque. In addition, Patent Literature 2 discloses an agent for oral cavity obtained by filling a liquid composition for oral cavity containing an anionic surfactant such as phosphate monoesters into a container, and the composition is directly applied in the form of foam with the intention of enhancing usability and the like.
Furthermore, Patent Literatures 3 to 4 disclose a foam composition for oral cavity filled into a non-gas normal pressure container, the composition containing an anionic surfactant, a nonionic surfactant or an amphoteric surfactant in each specified amount, which intends to improve dispersibility, foam quality and the like in the oral cavity.
(Patent Literature 1) JP-A-2000-44448
(Patent Literature 2) JP-A-10-167943
(Patent Literature 3) JP-A-08-333226
(Patent Literature 4) JP-A-09-295923